Raman and IR studies of surface metal oxide species on oxide supports: Supported metal oxide catalysts

Temperature-programmed reduction of CoOAI2O3 catalysts

https://www.lehigh.edu/operando/Publications/2005%20Recent%20Conceptual%20Advances%20in%20Catalysis.pdf

Recent conceptual advances in the catalysis science of mixed metal oxide catalytic materials

Publisher Summary The forms of active components present in heterogeneous catalysts are of importance to catalysis A supported catalyst usually consists of an active component dispersed on a support with a highly specific surface An active component dispersed on a support may end up in one of three forms: (1) it may retain its chemical identity as a separate crystalline or amorphous phase, (2) it may form a new stoichiometric compound with the support or additive, or (3) it may dissolve in the support to give a solid solution This chapter provides a review of various aspects of the phenomenon of spontaneous monolayer dispersion, its nature, effects, and applications Spontaneous monolayer dispersion of compounds on supports is a widespread phenomenon and displays many unique effects The principles involved have applications not only to heterogeneous catalysis, but also to materials science and other related fields

Spontaneous Monolayer Dispersion of Oxides and Salts onto Surfaces of Supports: Applications to Heterogeneous Catalysis

Combined UV−vis diffuse reflectance spectroscopy (DRS) and Raman spectroscopy were applied to examine the electronic and molecular structures, respectively, of well-defined W(VI) bulk mixed oxide reference compounds consisting of (i) isolated WO4 or WO6 monomers, (ii) dimeric O3W−O−WO3, (iii) polymeric chain of alternating WO4/WO6 units, and (iv) WO6-coordinated W9−W18 clusters. Raman spectroscopy was employed to confirm the identity and phase purity of the different tungsten oxide structures. UV−vis DRS provided the corresponding electronic edge energy (Eg) of the ligand-to-metal charge transfer (LMCT) transitions of the W(VI) cations. A correlation between the edge energy and the number of covalent bridging W−O−W bonds around the central W(VI) cation was found with Eg linearly decreasing with increasing number of bridging W−O−W bonds. However, a direct relationship between Eg and the domain size, NW, for finite WOx clusters does not exist. Subsequently, UV−vis and Raman spectroscopy information were app...

/pdf/structural-determination-of-bulk-and-surface-tungsten-oxides-2ugkedv1vz.pdf

Structural determination of bulk and surface tungsten oxides with UV-vis diffuse reflectance spectroscopy and raman spectroscopy

https://pure.tue.nl/ws/files/2143139/620503.pdf

Characterization of Silica-Supported Molybdenum Oxide and Tungsten Oxide. Reducibility of the Oxidic State versus Hydrodesulfurization Activity of the Sulfided State'

Raman spectroscopic investigation of the effect of H2O on the molybdenum surface species in MoO3Al2O3 catalysts

https://pure.tue.nl/ws/files/1724050/620501.pdf

R Thomas

Papers

Characterization of Silica-Supported Molybdenum Oxide and Tungsten Oxide. Reducibility of the Oxidic State versus Hydrodesulfurization Activity of the Sulfided State'

Raman spectroscopic investigation of the effect of H2O on the molybdenum surface species in MoO3Al2O3 catalysts

Structure/metathesis-activity relations of silica supported molybdenum and tungsten oxide

A comparative study of γ-alumina supported molybdenum and tungsten oxide: relation between metathesis activity and reducibility

Laser-Raman spectroscopy of the alumina-supported rhenium oxide metathesis catalyst